Tex. Tax Code § 171.807

(a) The comptroller may award a credit to a taxable entity that applies for the credit under this subchapter if the taxable entity is eligible for the credit and the credit is available under Section 171.805(b).

(b) A taxable entity must apply for the credit in the manner prescribed by the comptroller and include with the application any information requested by the comptroller to determine whether the entity is eligible for the credit under this subchapter. The comptroller may adopt rules prescribing the application process for the credit, including rules prescribing:

(1) a process by which the credit is awarded on a first-come, first-served basis;

(2) an enrollment period with application deadlines to submit an application for the credit;

(3) a requirement that a taxable entity must apply for the credit using an electronic application; and

(4) the information required to be submitted with the application for the credit, including the certificate of contribution described by Section 171.804(b).

(c) A taxable entity may not apply for an amount of credit greater than the lesser of:

(1) the taxable entity's designated contributions made to eligible organizations during the relevant period; or

(2) $1 million.

(d) A taxable entity may be awarded an amount of credit less than the total amount of credit to which the entity would otherwise be entitled if awarding the entity the total amount of credit would exceed the limitation under Section 171.805(b).

(e) The comptroller shall notify a taxable entity in writing of the amount of credit, if any, awarded to the entity.

(f) The award or denial of a credit under this subchapter and the amount of any credit awarded is not a contested case under Chapter 2001, Government Code.

(g) Subject to the limitations prescribed by this subchapter, a taxable entity may claim the amount of credit awarded by the comptroller on the report originally due after the entity receives the notice described by Subsection (e).